1. Field of the Invention
The present invention relates to an electronic device including a printed circuit board having electronic circuit components mounted thereon, and a housing having the printed circuit board received therein.
2. Description of the Related Art
Hitherto, an electronic device including a printed circuit board, a case, and a cover has been known. The printed circuit board has a plurality of electronic circuit components mounted thereon by soldering at joining portions, and also has a surface on which conductive members are exposed. The case has the printed circuit board received therein. The cover is formed of a conductive member opposed to the surface of the printed circuit board on which the conductive members are exposed. The printed circuit board is fixed to each of the case and the cover with screws. Terminals of a connector are inserted into through holes of the printed circuit board so that the connector is electrically connected to an electronic circuit in the printed circuit board. This electronic device is disclosed in, for example, Japanese Patent Application Laid-open No. Hei 8-148842 (FIG. 2 and FIG. 3).
However, in the above-mentioned electronic device, the printed circuit board is fixed to each of the case and the cover with screws, and hence the following problems have arisen.
(a) Stress may be generated in each of the joining portions of the electronic circuit components due to an error in dimensions including warpage of the printed circuit board or an error in a mounting position of the printed circuit board, thereby causing breakage in each of the joining portions.
(b) The printed circuit board may be warped due to differences in thermal expansion between the printed circuit board and the case and between the printed circuit board and the cover so that stress is generated in each of the joining portions of the electronic circuit components, thereby causing breakage in each of the joining portions.